As an English speaking member of this English forum, I understand the nouns 'pederasty' and 'pederast' to be 'sexual activity involving a man and a boy' - ie. it has a 'homosexual' specific slant, with both parties being male, and with one of them generally 'under-age'.
https://en.wikipedia.org/wiki/Pederasty
https://en.oxforddictionaries.com/definition/pederasty
Interestingly the Wikipedia article states specifically that 'pederasty is not to be confused with pedophilia'
https://en.wikipedia.org/wiki/Pedophilia
https://en.wikipedia.org/wiki/Child_sexual_abuse
Therefore, considering that I understand that the word isn't originally English, but like a lot of English words is derived from the Greek, how are we to understand the use of 'pederasty' in other langauges, for example Spanish, which, as Nathan Natas said, has a English problem of "pronoun poisoning"
The query is due to the - linked below - article in the Spanish newspaper El Periódico that appears to use 'pederast' in relation to 'adult male / child female' - but the translation is confusing due to the genders of the nouns in Spanish.....